Field of the Invention
The present invention relates, in general, to a technique to detect a gear step in a non-contact manner, and more particularly, to a gear detection switch for detecting a gear step, which is driven in a non-contact manner based on a Hall device, thereby operating semi-permanently, compared to a contact-type switch.
Description of Related Art
Generally, although a gear detection switch for a vehicle, which is mounted to a manual transmission, consists mainly of a mechanically contacted type switch, for the purpose of improved responsiveness, prolonged lifetime, manufacture of eco-friendly parts, etc, and due to distribution of hybrid electric vehicles (HEV) or electric vehicles (EV), a non-contact gear detection switch using a Hall device (or Hall IC) has been introduced to vehicles.
A control finger and a rail, which are mounted in a transmission (particularly a manual transmission), are interconnected with a gearshift lever, and in a case where a contact type gear detection switch is mounted therein, when driven by a driver, they rotate about a control shaft so that the rotated control finger press-touches a connection terminal of the switch, thereby generating and transmitting an electrical shift signal.
In contrast, in a case where a Hall device based non-contact type gear detection switch is mounted, the switch generates an electrical shift signal using a Hall voltage which is created by an air gap between the rotating control finger and the switch, and transmits the electrical shift signal.
A conventional contact type gear detection switch is configured such that, when a push rod is pushed by a control finger, a moving contact, which is mounted in the switch, comes into mechanical contact with a terminal to generate a shift signal and then the switch transmits the shift signal to a transmission control unit (TCU). However, the contact type switch has a problem in that a lifetime is relatively short compared to a non-contact type switch, because the switching operation is based on mechanical friction contact.
Further, a conventional non-contact gear detection switch also has a problem in that magnetic polarity of a magnetized magnet, which should be manually mounted in the switch, is misaligned in assembly, causing an error. In addition, in the case where a housing has a press-fit assembly structure, moisture and foreign substances may be easily externally introduced into the housing through the assembly structure. Furthermore, when the housing is resin-molded, the internally mounted magnetized magnet cannot resist the molding (injection molding) temperature, so the magnetic field of the magnet decreases in intensity due to high temperature demagnetization, resulting in reduced operation performance of the switch.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.